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ANA CABRERA, CNN NEWSROOM SHOW HOST: You're in the "CNN Newsroom." Thanks for being with us on this Sunday. I'm Ana Cabrera in New York.

CLARISSA WARD, CNN SENIOR INTERNATIONAL CORRESPONDENT: And live in London, I'm Clarissa Ward.

CABRERA: London is a city still in shock right now, just 24 hours since a horrific and deadly terror attack. Seven people are dead, more than 35 others and many of them still in the hospital, most in critical condition.

WARD: A large part of London including the famous London Bridge is a crime scene right now, roped off to the public, while police look for any evidence that will help them put together what happened and help them learn who else might be responsible. The three men who drove a van into people walking on London Bridge then started stabbing and slashing people in restaurants -- they are all dead, taken down by London police.

CABRERA: And police have been raiding parts of London arresting people they believe had a hand in planning or carrying out the London attacks. Right now, police have 12 people they've arrested.

(BEGIN VIDEO CLIP)

MARK ROWLEY, ASSISTANT COMMISIONER, METROPOLITAN POLICE: We are making significant progress in identifying the three attackers and confirming the fact that there were no other suspects at the scene when the attack was carried out.

(END VIDEO CLIP)

CABRERA: CNN cameras, crews and reporters are all over London right now. We are covering the aftermath of these awful attacks. The families of the victims, the people hurt, the police response and the people of London living in a city attacked again.

WARD: Well we begin with our international diplomatic editor, Nic Robertson, who joins me now. Nic, what are police learning about the men who carried out these attacks? NIC ROBERTSON, CNN INTERNATIONAL DIPLOMATIC EDITOR: Well, the police

say that this is a continuing investigation with continuing at a swift pace. They have made significant progress in identifying those three men involved in the attack. They say that one of them rented the white van that was used in the attack.

The 12 arrest and searches that have come in the Barking (ph) in the east of London today, do seem to indicate the police suspect that these men may have come, may have been living in the east of London prior to this attack. Why can we surmise this? Because looking at what the police have done after recent attacks, the people, the properties that they go to in the immediate aftermath, the first properties they tend to go to tend to be the properties where the attackers have been living or have had close friends and associates.

So that's why we can begin to surmise this that potentially those attackers came from London. Of course the police not identifying them even, asking journalists to pixelate or cover the images they may have of the attackers shortly before the attack. The police want to continue this investigation at their pace, uncovering leads at their own pace without any tip offs to journalists or to the public about who the attackers might be. Much controversy over that following the Manchester attacks that they seem to be avoiding that so far.

So the 12 arrests, the police are not saying who they are. And it's important to remember perhaps at this time that often when police make so many arrests in the early hours and days after an attack, many of those people are released after questioning. But what the police want to do is figure out are there anymore attacks imminent, are any of those close associates likely to know other potential attackers, could they be radicalized or others. But the police saying they believe these three attackers were working alone in this attack. But of course, we want to know so much more. Clarissa.

WARD: OK. Nic Robertson, thank you so much.

While there was chaos and confusion around London Bridge last night, one man talked to our Becky Anderson about what he saw when he came upon the scene shortly after the attack.

(BEGIN VIDEO CLIP)

TYSON OLADOKUN, EYEWITNESS: As I drove closer towards the incident, I saw a man lying on the floor. He was cradled by another man and had blood on his chest. I thought as it looked like a bicycle accident or motor accident, but as I move closer towards him, I could tell the blood was concentrated in his chest area so it looked like he had been stabbed.

I saw another person lying down next to him and they covered his head with blanket so it did look like this guy may have died. We were stuck there for around 30 minutes or so. We weren't moving. There was a lot of commotion, people were going crazy. The police seemed relatively calm at the time, it was only subsequently I saw quite a lot of police and they wear chasing people across the bridge. This was normal civilians or pedestrians over the bridge and screaming at them to run, run, run for your lives.

(END VIDEO CLIP)

WARD: Forty-eight people were wounded in the attacks,

[17:05:01] 36 of them are still in the hospital. Our Saima Mohsin is outside King's College Hospital where many of the wounded were taken. Saima, what's the latest where you are?

SAIMA MOHSIN, CNN CORRESPONDENT: Well, Clarissa, there is still a police presence this evening. There are police dotted around the perimeter of this hospital, one of five hospitals that the victims were taken to. Of course minor injuries were dealt with at the scene at the time, but those seriously and critically injured were taken to five hospitals across the city.

Now, at King's College Hospital, 14 were brought in. One of them has now since been discharged, 13 remain. The Prime Minister Theresa May came here today to visit the victims, their families alongside their bedsides as well. Now, that visit was kept under wraps of course because of security concerns right now but there was a large police presence while she was here this afternoon.

And then later, I managed to speak with a mother of one of the victims. With extraordinary composure, she described exactly how her son came under attack. Take a listen.

(BEGIN VIDEO CLIP)

ELISABETH O'NEILL, MOTHER OF VICTIM: She's friends and the police worked with the (INAUDIBLE) and the police have brought blue lights flashing, two police officers remained in the back with him and they had him lying across them and they placed pressure on the wound and I'm trying to find those police officers now to say thank you to them.

(END VIDEO CLIP)

MOHSIN: Those police officers acting in extreme heroism to bring him here, pressing down on his wounds, keeping him alive until they got to the hospital. And she also told me that her son, Daniel, feels guilty that he is one of the men who survived. Another extraordinary story as well, Clarissa, from the British Transport police officer who tried to tackle one of the attackers with only the use of his police baton. He had nothing else to combat him with but the British Transport police describing how he showed extraordinary and enormous courage in tackling that attacker. He remains in a serious but stable condition in hospital.

And those stories coming through us of course as people are now able to speak and those victims are able to tell and recount the stories of what they went through. The hospital also, Clarissa, tonight is asking people not to contact them directly if they're concerned but to contact the Metropolitan Police casualty bureau line that's being set up. They are still overwhelmed dealing with this, which still a major crisis for them. Clarissa.

WARD: All right, Saima Mohsim with incredible stories of heroism amid the terror. Thank you so much. Ana, back to you in New York.

CABRERA: So much bravery. And we continue to get on top of the latest developments there out of London. Meantime in Manchester, there is an ongoing investigation there too. Investigators continuing to dig into the attack less than two weeks ago it happened, and then the show went on this weekend. Singer Ariana Grande taking the stage for a benefit concert that is still going on right now.

The concert was meant to send a message, a message of unity and love and to pay tribute to the victims of the suicide bombing there on May 22nd, the last time Grande performed in Manchester. Of course it all comes less than 24 hours after the deadly terror attack in London. CNN international correspondent Phil Black is joining us from the venue there in Manchester. Phil, it looks like a packed site. Ariana Grande was just determined to have this benefit concert despite the high terror alert in the U.K.

PHIL BLACK, CNN INTERNATIONAL CORRESPONDENT: Yes, she was, and what we've been seeing just now have been the crowd giving their final thanks, their final cheers to Ariana Grande as this concert just wraps up. Behind me there has been a sea of smiling, happy, dancing, cheering, singing people from Manchester.

The atmosphere really truly incredible as they have showed their appreciation for an amazing lineup of international pop superstars, not just Grande, but Katy Perry and Pharrell Williams, Miley Cyrus, Justine Bieber.

On any day anywhere in the world, this would have been a truly amazing concert or an extraordinary spectacle. But here, because of the motivation behind it, the feeling, the emotion, it has been lifted to really a truly unforgettable night. Ana.

CABRERA: Understandably security though is heightened at that stadium there in Manchester. What can you tell us about that?

BLACK: Incredibly strict security around the ground where this is taking place. There have been police everywhere. The crowd was largely kept outside for the better part of the day. They were patient and happy but

[17:10:00] on the way in, it was a very slow process, everyone was searched, everyone was checked until finally the space behind me late this evening was eventually filled with a huge crowd enjoying this though tonight. Ana.

CABRERA: So happy to see happy crowd and some moments of lightheartedness despite the back drop. Phil Black, thank you. And we are now hearing about one of the first victims named after the tragedy in London. The Canadian government confirming one of its citizens was killed. Her name is Chrissy Archibald.

In a statement, her family wrote, "we grieve the loss of our beautiful loving daughter and sister. She had room in her heart for everyone and believes strongly that every person was to be valued and respected. She lived this belief working in a shelter for the homeless until she moved to Europe to be with her fiance. She would have had no understanding of the callous cruelty that caused to her death. Please honor her by making your community and better place. Volunteer your time and labor or donate to a homeless shelter. Tell them Chrissy sent you."

This is the Archibald family statement. So again, one of seven victims, seven people, innocent lives taken too soon by the heinous acts of three individuals. We also have an update just crossing into CNN right now from the metropolitan police as they're continuing their investigation. We now know of the 12 people arrested, one has been released. We are told that all the arrests were made in the Barking area of London and four properties are still being searched.

And we're also learning seven of those arrested are female. Again, we're staying on top of new developments coming in from London here in the newsroom. Three attacks in three months. Has Britain and Europe for that matter, become more vulnerable? Plus, a van and a knife, the sheer simplicity of this attack is just chilling. What this could tell us about how terror tactics have evolved.

And later, some breaking news, breaking his silence, fired FBI director James Comey set to testify on Capitol Hill Thursday. What will he say and can the president move to block his testimony? You're live in the "CNN Newsroom."

[17:15:00] (COMMERCIAL BREAK)

CABRERA: A few numbers from this latest terror incident in the United Kingdom, three attackers, they're all dead. Seven innocent people just waking on London Bridge or spending a Saturday night in a restaurant there, also dead. Dozens of people are hurt, many have been critical and 11 people are now in police custody.

Police in London are working to figure out their connection to the attacks and if they played a part. I want to bring in CNN terrorism analyst, Paul Cruickshank is with us from London and CNN's law enforcement analyst James Galliano is here with me in New York. Paul, to you first, I understand you're learning new information about those arrested.

PAUL CRUICKSHANK, CNN TERRORISM ANALYST: Extraordinary new details. Out of 11 people in custody right now, 7 of those are women, ranging between the ages of 19 and 60, most of them arrested at one location in Barking, but a significant number of women have been arrested in the aftermath of this attack. They have not been charged with any crimes at this point.

But it's certainly a very interesting detail that we're learning. And of course when we've looked at ISIS inspired terrorism, these extremist networks in the west, they've been a social movement, men and women have been involved. We've had significant radicalism of women in the west. More than 500 of them that have traveled to join in this sort of jihadi movement in Syria and Iraq from the west.

So, very significant new details here, that a significant number of women, 7 out of the 11 now in custody in relation to this plot, this attack, that its quite extraordinary with what we're learning. We'll have to find out much more in the hours ahead.

CABRERA: James Galliano, it seems like investigators are making quick work. It was about this time yesterday, of course we were sitting on set and this incident happened. It was unfolding. How important are these first 24 hours?

JAMAES GALLIANO, CNN LAW ENFORCEMENT ANALYST: They are exceedingly important, Ana, because obviously you want to be able to get as much, harvest as much of the forensic intelligence as you can and you also want to get with as many witnesses as possible early on, because people's memory tend to fade.

I think what we're seeing here now is we're making an adjustment in the west and this being the age of ISIS and the new normal that we're confronting in the fight against terrorism. The days of Carlos the Jackal in the '70s where the mastermind was actually on the front line conducting terrorist attacks are over. ISIS is going to continue to work this way, which is centralized intent which is put out on the internet and through globalization it gets shared everywhere and decentralized execution. And that's what London and the U.K. in particular for the last couple of months have had to deal with three separate attacks, decentralized execution.

CABRERA: And yet, Prime Minister Theresa May says these three attacks over the course of three months are not connected. We also learned they've arrested 12 people today and one of those people released, what does all that combined tell you?

GALLIANO: I was heartened to see here come out and speak as strongly as she did. First of all, in an abundance of caution right after the attacks happened, you don't want to immediately come out and announce this is a terrorist attack. But in the law enforcement end, we automatically have to presume that until proven otherwise. But before you want to go public, I felt like she waited to the appropriate amount of time before she got the intel back from the first responders that that's what it was.

Now going forward, these were three separate cells and these cells were like needles in the proverbial haystack. They're difficult to find, and even if you find them, remember in the west, we can't arrest people for thought. So, if we think that they might be up to something, that's not good enough. So we got to provide and expand

[17:20:00] the resources to follow these people and try to get people in the inside to disassemble it before obviously what happened last night.

CABRERA: We know there were 17 people that have been arrested in the Manchester attack. Now we're learning 12 people initially arrested in the first 24 hours after this attack, Paul. And then there was of course that other attack that happened on Westminster Bridge in London back in March. What's going on in the United Kingdom? All these attacks happening in such a close amount of time with multiple people involved?

CRUICKSHANK: That's right. There's already been a surge in ISIS inspired terrorist plotting in the U.K. There also have been five thwarted attacks, plots since the Westminster attack. The threat picture is darkening here in the U.K. There are just a very large number of extremists they're having to monitor -- up to 3,000 individuals who are considered potentially dangerous over the years since 9/11.

They've also historically monitored another 20,000 individuals who they have thought to have posed a residual threat. And frankly, even if you tripled and quadrupled the resources available to British counter-terrorism, that would be nothing like what you would need to follow such a large number of people intensively. So they have to do a certain amount of triaging every week, making judgment calls about who to follow, who not to follow, and of course sometimes they get those calls right and sometimes they get those calls wrong.

What we don't know at this point is whether these three attackers were previously somehow on the radar screen with British security services. That is not clear at this hour. But we're really entering a very concerning period now as we move forward in a few days to this election in the U.K. and also during this holy month of Ramadan in which ISIS have called on their followers in the west to surge terrorist attacks. And of course a year ago during Ramadan, we saw the Orlando shootings during that period. Also ISIS have put similar calls out so, a concern on both sides of the Atlantic over the next few weeks. Ana.

CABRERA: James, why do you think Britain is vulnerable right now? Is it different in terms of the scenario, the bigger picture there than the U.S. and what we may be dealing with?

GALLIANO: Sure. I think on the geopolitical, and Ana, what we're looking at is the people that have argued for Brexit and said that this is a result of the refugee situation and being part of the E.U. I tend to try to look at things from a moderate perspective. I look at Sadiq Khan, the mayor of London versus our president. And I think both are kind of on the ends of the continuum. We have to find some place to meet in the middle.

We are playing game of whack-a-mole right now. And on the one side, we want to look at things and say, well this is just nebulous, ambiguous -- we don't really know what this is. And then on the other side, we want to say travel ban, Muslim ban and we've, you know, go to be hyper vigilant, which we do need to do but we need to target one particular segment of the population.

We got to find some place in the middle. We go to spend some place where we can hyper vet folks that are coming in. Extreme vetting I think it's being described as, and at the same time, make sure that we're conducting outreaches to the Muslim community to say, hey, we need your help. We're not targeting you but we got to --

CABRERA: A lot of the recent attacks were homegrown. They weren't from people who are outside coming in.

GALLIANO: Right. But you're sitting in front of a computer. So, when you say homegrown, they don't have to travel to Syria anymore, they sit down, flip open a computer and bam!

CABRERA: There's a cyber component.

GALLIANO: They are right there in the Middle East and they are listening to some radical imam telling them that what they need to is go out and kill westerners. And unfortunately we find this segment of our population is disenfranchised and is living in their parents' basement and they're not assimilated. They've come to the country whether it's Britain or the United States and they live in a cloistered community, that's their connection, their connection to the world and the connection to "reality" so we have to stop it.

CABRERA: Jim Galliano and Paul Cruickshank, our thanks to both of you.

While many world leaders are offering sympathy to London, President Trump had a different reaction to this terror attacks, using it to push for his travel ban and to slam London's mayor for his own response. That's next. You're live in the "CNN Newsroom."

[17:25:00] (COMMERCIAL BREAK)

CABRERA: While world leaders call for unity in the wake of the terror attack in London, President Trump seems to be using the opportunity to promote his own agenda. In the moments after the attack last night, President Trump took to twitter to push his proposed travel ban and then today, he criticized the mayor of London tweeting, "At least seven dead and 48 wounded in terror attack and mayor of London says there is no reason to be alarmed." Now, the mayor of London did say people shouldn't to be alarmed by seeing an extra police presence. Here's the full context.

(BEGIN VIDEO CLIP)

SADIQ KHAN, MAYOR OF LONDON: Londoners will see an increased police presence today and over the course of the next few days. No reason to be alarmed. One of the things the police needs to do is make sure we're safe as we possibly can be.

(END OF VIDEO CLIP)

CABRERA: We'll talk more about the president's reaction to this latest terror rampage. Joining us now, CNN political analyst and Princeton University professor, Julian Zelizer. Also, political commentator and former spokesman for Republican Congressman Darrell Issa, Kurt Bardella.

Julian, you wrote an opinion piece for CNN.com and you write, "The president who is preparing to bring his blocked travel ban to the Supreme Court has chosen to use this moment of fear as justification to build public support for his controversial executive order." Do you think that's what's going on here?

JULIAN ZELIZER, CNN POLITICAL ANALYST: It was kind of astounding after this horrific attack in London, if you just follow the tweet trail. One is about the travel ban and basically saying, look, this is why we need the travel ban here, which has been tied up in the courts and the administration wants to bring it to the Supreme Court.

He also attacked political correctness, gun control and the mayor of London, all within the span of a few hours.

CABRERA: He made this political.

ZELIZER: He made it very political. You follow the horrific attack in London, this is why you need this travel ban. It's been tied up in the courts and he attacked political correctness and gun control and the mayor of London

[17:30:00] all within the span of a few hours.

CABRERA: He made this political.

ZELIZER: He made it very political and issues that are not all related to the attack that actually took place. SO, I think many people are pretty shocked to see him say this or write this and that's his first response.

CABRERA: You're worried about that response?

ZELIZER: Well, there's a history of playing to the politics of fear when we have true threats and genuine problems here and abroad from adversaries. Sometimes presidents and politicians play to the worst in us. They play to these fears and they use that to drum up support for other parts of their agenda.

We had a red scare during World War I for example, which led to the imprisonment of many people because they were too far to the left politically. So, I think it's a concern. I think it's a concern because of that, and what does this say to the leaders of other countries that this is what's on the president's mind rather than the actual problem that happened in London.

CABRERA: Kurt, the acting U.S. ambassador to the U.K. is directly contradicting President Trump tweeting this, "I commend the strong leadership of the mayor of London as he leads the city forward after this heinous attack." What do you make of this two confliction messages coming from the president and somebody on his own team?

KURT BARDELLA, POLITICAL COMMENTATOR: Well, you know, it's refreshing to see somebody at least in the administration act responsibly. It will be interesting Trump and lieutenants react to this. I think it's also (INAUDIBLE) I'd like to see what Secretary of Stat Tillerson thinks about all of this as well. It's been very unusual that the only response that we've seen from this administration to this terror attack is on twitter, from the president and his director of social media went on twitter and attacked the mayor of London.

And it's downright insane that the leader of the free world chooses these types of moments to just act out and use them in a way to try to play off our own worst fears to advance an agenda that's designed to make America more isolationist rather than doing the responsible thing and expressing support for the people of London, pledging to do whatever we could to try to help their situation, not instigate fear, not instigate chaos. That is the last thing that we need both in the United States as well as around the world.

CABRERA: Just this week, the White House communications director resigned, Sean Spicer started giving off camera briefings. Can this administration have a successful communication strategy as long as the president is tweeting?

BARDELLA: No, they can't, because the reality is anybody, whether you're the White House press secretary or spokesperson or surrogate on TV, whatever you say can and most likely will be contradicted by the president himself in a 200 character tweet. So, there is no point at all really to even listening to any of these surrogates or any of these administration officials because often the president is going to do whatever he wants to do.

He's proven that he's not going to change. This is a 72-year-old man who will never change his ways and every time that there's a moment where people think, well, maybe he's going to seize the moment and now he's officially president, he undermines it later on with a tweet. He's not going to change.

CABRERA: Julian, how much is a disadvantage right now that there is no ambassador to the U.K. that the president has nominated? This person is a holdover from the Obama administration. We also have several State Department positions that haven't been filled. Is that an issue?

ZELIZER: It's a huge weakness. I think the fact that we have undermined our diplomatic core at a moment like this is very damaging in terms of what do we do to respond to these kinds of attacks. The response is not something military. The response also has to be diplomatic with our allies, and even dealing with our adversaries but we don't have anyone doing that. This has been a problem people had been talking about. And I think it makes us much less effective, and when you have a president who tweets these kinds of things, there's that much more reason that you need a strong diplomatic core to try to heal some of this, but there is no one doing that work.

CABRERA: All right, Julian Zelizer, Kurt Bardella, thank you both.

Coming up, it could be one of the most important testimonies since Watergate, former FBI director James Comey set to testify this week for the first time since being fired by President Trump. What he might say, next. You're live in the "CNN Newsroom."

[17:35:00] (COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

(SINGING)

(CROWD CHEERING)

(END VIDEO CLIP)

CABRERA: And that is how Ariana Grande closed out her concert this evening in Manchester. This just in, Ariana Grande's "One Love Manchester Concert" and the pop princess sharing a touching story of meeting the mother of one of the young victims of the May 22nd suicide bombing after her last concert in Manchester. Listen to this.

(BEGIN VIDEO CLIP)

ARIANA GRANDE, SINGER: And I want to also say I had the pleasure of meeting Olivia's mommy a few days ago. And as soon as I met her, I started crying and gave her a big hug. And she said that stop crying because Olivia wouldn't have wanted me to cry. And then, she told me that Olivia would have wanted to hear the hits.

(END VIDEO CLIP)

CABRERA: We are continuing to follow the breaking news out of London. But I want to turn for just a moment to another major story this week. On Thursday, former FBI director James Comey will publicly testify. It is the first time we'll hear from him directly since he was suddenly fired by President Trump. He is said to be eager to talk about his private discussions with the president -- discussions that reportedly made him so uncomfortable he made detailed notes afterwards.

Joining us to discuss, professor emeritus at Harvard Law School Alan Dershowitz. Professor, thanks for being with us. Comey's testimony is being compared by some to that of Anita Hill from the 1990'. She testified that she had been sexually harassed by future Supreme Court Justice Clarence Thomas. Do you agree with this comparison about just how

[17:40:00] big of a deal this is?

ALAN DERSHOWITZ, PROFESSOR EMERITUS, HARVARD LAW SCHOOL: No. I think it's a very, very small deal because we have the notes and he's not going to straighten the notes. So, there are going to be no major surprises. In fact, I think --

CABRERA: But we don't have the notes yet. We just heard what the notes reportedly say.

DERSHOWITZ: And the notes will come out. He has the notes. He knows what the notes say, and so he's going to stick very, very close to the notes. And the reason this may end up being good for Trump, not bad for him, is that there will be an opportunity for the Republicans to cross examine him, and they will cross examine him very, very harshly.

He is turned out to be hated by both the Democrats and the Republicans. The Democrats because they believe he turned the election over to the Republicans and the Republicans because they now think he's turning against their president. So he's going to have a pretty hard time in front of that congressional committee.

And the other myth that has to be dissipated is the myth that somehow Mueller has to give him permission to testify. Congress comes first. The Justice Department comes second. Congress is an independent branch of government and they have the right to subpoena and demand the notes and he can't just say, I don't want to turn them over to you because the Justice Department wants to see them first. Congress has the absolute power to compel him to turning these materials over.

CABRERA: OK, OK. So Trump is said to have asked Comey for loyalty, according to some of these memos, those who know Comey and some of their interactions. He reportedly asked Comey to drop the investigation into Michael Flynn as we have reported here on CNN. Democrats are likely to ask if Comey believes the president was trying to obstruct justice. What if Comey's answer is yes?

DERSHOWITXZ: Well, Comey -- if he were to testify at a trial, he wouldn't be allowed to testify what his feelings were or whether he believed there was an obstruction of justice. That's a legal conclusion. Here I suspect that he may answer that question and I think he's stuck because if he thought it was an obstruction of justice, he had an obligation to pursue it further and he didn't pursue it.

I think he's going to have to say, look, he wasn't told to do this, he was asked would it be possible for you to do this. Now, of course, being asked by the president he might say is like getting a kiss from the godfather, it's an offer you can't refuse. But I think he's going to stick pretty close to the text of the notes.

He knows there are notes. He knows that nobody (INAUDIBLE) whether there were tapes in the Oval Office or at his dinner. I doubt there are. If he doesn't know that for sure, and therefore I think he's not going to depart fundamentally from what is the written records. So the written record is the key.

Those memos are contemporaneous. They don't require remembering things that happened a long time ago. They don't have spin. And so I think that the records, written documents will be far more important than the oral testimony.

CABRERA: So it sounds like you're not expecting any bombshells. Now the White House has not explicitly said whether Trump will use executive privilege to try to block Comey's testimony. What would you advise him to do?

DERSHOWITZ: Absolutely not. It would be a terrible mistake to do that and it will fail. There is no legitimate claim of executive privilege I believe for a conversation like that. Also, he no longer is in government service so he doesn't have to listen to the president. The president would have to go to court and get a court to compel Comey not to testify.

I think if they were going to do that they would have done that already. So, I anticipate we will hear the testimony, he may claim that he can't answer some questions because the Justice Department has told him not to.

CABRERA: Right.

DERSHOWITZ: That's a claim that Congress should absolutely and categorically reject. They have the right to hear this testimony first. They are more important than the Justice Department because Congress has the power to impeach the president and the Justice Department probably doesn't have the power to indict the president.

CABRERA: So what do you make of the fact that we've been told Comey has gone over the parameters of his testimony with special prosecutor, Robert Mueller. What do you think that means for his testimony, if anything. It sounds like you're saying that it shouldn't mean much.

DERSHOWITZ: Well, first of all, if I were the Republicans I would ask him to relate the conversations he had with Mueller, every single one of them. I don't see any claim of privilege that he could make there. Let's get it on the record and see what he said to Mueller and what Mueller said to him.

I think the key is going to be the words he spoke. The words he spoke to the president the words the president spoke to him. Remember, he didn't give the president's request, the president said to him, go easy or whatever the words were on the general, but he didn't. He didn't drop the investigation.

So, it's going to be hard for him to say that there was an obstruction of justice or that there was even an attempt to obstruct justice. But I think politically, President Trump

[17:45:00] could be made to look weak or bad if Comey decides to spin it in a certain way. But he is locked into basically repeating what he knows are in those contemporaneous memos. He's not going to depart from them very far.

CABRERA: Now, we heard Sean Spicer this week referring all Russia investigation questions to Marc Kasowitz. Now, Kasowitz is the president's personal lawyer, not the White House counsel. Does it make sense for him to now be the one to speak on behalf of the White House regarding the Russia investigation?

DERSHOWITZ: This is going to be a very difficult job for the White House counsel and for Kasowitz, who is a very, very good lawyer, because there are certain issues that are related to the presidency themselves and there are certain issues that related to Mr. Trump. Any questions regarding anything that happened before he became president have to be responded to by his personal legal team.

But questions that arose while he was president, for example his conversations with Comey, the White House counsel's office, appropriately can respond to those, but there's going to have to be a legal team and there's going to have to be coordination between the White House counsel's office, which represents the presidency and Mr. Kasowitz who represents Donald Trump the individual.

CABRERA: All right, Alan Dershowitz, always good to hear your expertise on our show. Thank you. You're live in the "CNN Newsroom." Next hour, much more of our breaking news coverage of the London terror attack. Eleven people now in custody, seven of those are women. We are staying on top of the investigation and President Trump's much criticized response to the attack, all here in the "Newsroom." Stay with us.

[17:50:00] (COMMERCIAL BREAK) CABRERA: Breaking news into CNN. A claim of responsibility for last night's vicious terror attack in London -- ISIS is claiming to be behind that attack. I want to bring in CNN terrorism analyst Paul Cruickshank joining us from London. Paul, you just confirmed this information. Do we know yet is this ISIS inspired or ISIS directed?

CRUICKSHANK: Well, just in the last few minutes the ISIS affiliated agency, Amaq, has put out a statement claiming that the London attack was carried out by a detachment of ISIS fighters. Putting that statement out just in the past few minutes, but they have offered no evidence at all to back up that claim. And that's something that is very important to note. It's also very important to note that the same agency and indeed ISIS also claimed responsibility for that attack in Manila in the Philippines earlier in the week.

The Philippines government has said that that attack was nothing at all to do with terrorism and was carried out by an indebted gambler. So, a lot of question marks about the credibility of ISIS and its affiliated agency when it puts out these kinds of claims. No evidence at all to back this up. That said, it is clear that the London attack was an act of Islamist terrorism and we have seen many such attacks in the west being inspired by ISIS.

They've used this kind of language before in both attacks that they have -- they believe inspires and also in attacks which they directed. But they have also would appear put out false claims in the very recent past if what Philippine authorities have said is accurate.

CABRERA: It seems advantageous for them to take credit for all these different terror events. Paul, thank you very much. Of course, keep us posted as you learn more information. Now, police combing London at this hour and they are in the early hours of their investigation. Families peering out their windows watching the police. This is witness video. They are praying their families were safe. Up next, we're going to speak with the mother who took this video and who was evacuated from her home with her young son. That's next. You're live in the "CNN Newsroom."

[17:55:00] (COMMERCIAL BREAK)

CABRERA: Let's say your neighbor is planning a trip to Florida. Maybe they'd be willing to drop off your Aunt Mary's birthday gift on the way. Well, that's where Roadie comes in in today's segment of upstarts introduces you to a new app which connects shippers and drivers to get deliveries where they need to go. Take a look at how this works.

(BEGIN VIDEO CLIP)

MARC GORLIN, FOUNDER AND CEO, ROADIE: We have delivered everything from couches to kayaks to cupcakes to keys. We're opening up the wide space of an industry that really does exist in being able to get things places like you were never able to do before. My name is Marc Gorlin. I'm the founder and CEO of Roadie. It's actually a personal story to start Roadie. I had to replace a tile in the bathroom. I got a call from the tile guy and say where is this tile? How can I get a hold of it? He said I think it's in Birmingham about an hour and a half north of Montgomery.

I think to myself, if there's somebody leaving Birmingham right now heading to Montgomery. If I just knew who they were, surely they would throw a box of tile in their trunk. You post a gig of what you have and where it needs to go and people see what they're going to get paid to do it. You accept them and they take it.

We have over 350,000 downloads, nearly 30,000 drivers. We have a driver in every state in the country. We are a little over 30 employees now. We've raised two rounds of funding totalling $25 million. We got a bunch of musicians so, a song can break out at will. You have Nerf gun fights that break out at will around here. It's a community of people within the company that tries to do what we're doing outside, which is caring about each other.

Whenever you come up with a big crazy idea, there's going to be a million people that tell you why it can't work. It's so much easier to be an editor than a creator. Surround yourself of smart people that will tell you what you want to hear and what you don't want to hear.

(END VIDEO CLIP)

CABRERA: You're in the "CNN Newsroom." I'm Ana Cabrera in New York. Thanks for being with us. We're staying on top of the latest developments in London. A city vastly different than it was just last night, when a pleasant evening was shattered by a deadly terror attack. And breaking news, this just into CNN, ISIS is now claiming responsibility for that attack and the deaths of seven people.

[18:00:00] More on that claim of responsibility when I go live to London in just a moment. This is also some new information I want to share with you. Most of the 11 people arrested so far in this terror investigation are women.